Adjustable work surface for large irregularly shaped objects

ABSTRACT

An adjustable work platform comprises a fixed platform carrying a multiplicity of adjustable members designed to slide out of the fixed platform to variable lengths as needed. A large irregularly shaped object, such as an aircraft, may be driven into the interior of the platform with the adjustable members retracted. Once in place, the adjustable members are extended to form a heavy duty work platform conforming to the irregular shape of the exterior of the object.

FIELD OF THE INVENTION

This invention is directed to an adjustable work platform and, more specifically, to a heavy duty extendable platform designed to conform to the outer surfaces of a large, irregularly shaped object such as an aircraft.

BACKGROUND OF THE INVENTION

Maintenance upon large irregularly shaped objects is often difficult because of the cost and difficulty involved in providing safe and reasonably priced work surfaces suited to the outer size and shape of such objects. The variable shapes and sizes of large objects such as aircraft require custom work platforms so that workers can safely reach and work on those objects. Standard scaffolding is designed to facilitate maintenance upon standard rectangular shapes such as brick buildings. Custom scaffolding is known in the art but frequently cost prohibitive given the large variance in the size, shape, and number of objects that must be maintained in a typical setting, such as an airport hanger. To make matters worse, aircraft are subject to tight schedules to remain profitable, so maintenance time must be minimized. What is needed is an adjustable work surface that will accept a range of irregularly sized and shaped large objects quickly, safely, and efficiently.

SUMMARY OF THE INVENTION

The present invention alleviates many of the problems inherent with prior art work surfaces. The invention provides a novel system and method of use for an adjustable work platform that will accept a range of irregularly sized and shaped large objects quickly, safely, and efficiently.

An embodiment of the invention provides an adjustable work platform for carrying heavy loads in a stable manner comprising a fixed platform with a front side and a back side opposite thereto, with a first stringer along the front side comprising defined openings therein, a second stringer along the back side and a multiplicity of I-beam guides spanning between the first stringer and the second stringer, and an adjustable platform extendable from said fixed platform with a slider received by the adjacent I-beam guides and disposed to reversibly extend through one of said openings comprising a toothed member that reversibly engages with the first stringer thereby restricting sliding of said slider, and a back plate attached to the slider to limit the length of extension of said slider through the openings. The toothed member is rotatable about a perpendicular axis to the toothed member. The toothed member is also rotatable about a parallel axis to the toothed member. A back plate on the slider limits the lateral and vertical movement of the slider to provide increased stability of the slider.

A novel method of providing a work platform for carrying heavy loads while accessing an irregularly shaped object comprises the steps of providing an adjustable platform as described above, moving a large object to within a predetermined separation distance of the platform, and extending the adjustable platform from the fixed platform, minimizing the separation distance.

Another embodiment of the invention provides an adjustable walking surface for carrying heavy loads comprising a substantially horizontal platform having a first stringer disposed parallel to a second stringer and the first stringer and second stringer connecting by two or more I-beam guides that are perpendicularly disposed between the first and second stringer, a slider carried between two or more of the I-beam guides where the slider is operable to extend the horizontal length of the platform by pulling a first distal end of the slider through an opening the second stringer. A back plate is disposed upon a second distal end of the slider, where the back plate allows the slider to ravel horizontally along the lengths of the two or more I-beam guides while simultaneously preventing substantial vertical and lateral movement of the slider. A toothed member is disposed upon the downward facing portion of the slider, which operates to contact the lower vertical surface of the opening in the second stringer where a toothed member rests upon the lower vertical surface while the slider is in an extended position to prevent horizontal movement of said slider by force of gravity acting upon the slider until a greater upward force is applied to the first distal end of the slider followed by a horizontal force to extend or retract the slider.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective top view of an adjustable work platform.

FIG. 2 is a perspective bottom view of an adjustable work platform.

FIG. 3 is a horizontal view of an interior of an adjustable work platform with a fixed toothed member.

FIG. 4 is a horizontal view of an interior of an adjustable work platform with a pivoting toothed member.

FIG. 5 is a horizontal view of an interior of an adjustable work platform with a pivoting toothed member and release bar.

FIG. 6 is a perspective view of an adjustable work platform in use to perform maintenance on a helicopter.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to FIG. 1, a top perspective of an adjustable work platform is illustrated. Adjustable work platform 10 includes two stringers 12 a and 12 b connected by a series of I-beams 14 a, 14 b, 14 c, continuing to 14 n. A multiplicity of sliders 16 a, 16 b, continuing to 16 n are disposed between each of the I-beams. Each slider is extendable outward through opening 18 in stringer 12 b. The limit of extension for each slider is reached when a back plate on each slider contacts stop bar 20 or when rubber stop 22 contacts the object to be worked upon. Slider 16 b includes a set of stability tabs 21 a and 21 b, which are disposed on every other slider to increase the stability of all sliders once extended. These c-shaped members attach on the side portions of every other slider and provide a channel for each rectangular slider's extension.

Maintenance personnel can use the adjustable work platform sliders to create a suitably shaped work surface first by pulling a large irregularly shaped object, such as a helicopter, into a work bay with the adjustable work platform 10 disposed on one or more sides of the helicopter as illustrated in FIG. 6. When the helicopter is placed in the center of work platform 10, maintenance personnel then extend each of the sliders 16 a to 16 n outward by lifting the distal end of each slider and pulling outward to extend each slider through opening 18 until rubber stop 22 contacts the side of the helicopter. The weight of individual sliders, combined with a toothed member 24 illustrated in FIG. 2, holds each slider safely in place along the irregularly shaped outer surface of the helicopter. In this manner, adjustable platform 10 fills the gaps along the outer surface of the helicopter so that a safe and easily adjustable work surface is provided for maintenance on the helicopter.

Referring now FIG. 2, adjustable work platform 10 is shown from a bottom perspective view. Back plate 26 and stop bar 20 are illustrated in more detail. The maximum length of extension of sliders 16 a to 16 n is limited when back plate 26 contacts stop bar 20. Normally sliders 16 a to 16 n do not reach their maximum extended length, however, because rubber stop 22 is designed to contact the outer surface of the large irregularly shaped object.

As discussed with respect to FIG. 1, sliders 16 a to 16 n are positioned around the outer surface of an irregularly shaped object in the following manner. Once the object is placed adjacent to adjustable work platform 10, an operator extends each of the sliders 16 a to 16 n outward by lifting the distal end of each slider upward and pulling outward to extend each slider through opening 18 until rubber stop 22 contacts the side of the object. Once the desired length of extension of each slider is reached, the operator simply lowers the distal end of the slider so that toothed member 24 then contacts the lower surface of opening 18 on stringer 12 b. The rigidity of stringer 12 b, which is generally made of metal, combined with the shape and rigidity of the toothed member 24, which is also generally also made of metal, causes slider 16 to remain safely in place by force of its own weight.

Back plate 26 has several purposes. First, it provides a stop mechanism by limiting maximum travel of each slider to stop bar 20 as described above. Second, it provides additional stability by keeping the inner end of each slider firmly placed between each I-beam 14 a to 14 n. As discussed further with respect to FIG. 3, back plate 26 prevents unwanted lateral and vertical movement of each slider by completely filling the inner space between I-beams 14 a to 14 n. In this manner, the slider is allowed only minimal vertical travel on the distal end containing rubber stop 22, so that the toothed member pivots perpendicular to its own axis when an operator lifts the end to extend or retract a slider.

Thus an operator may easily and safely vary the length of extension of each slider 16 a to 16 n by lifting upward on the end of each slider where rubber stop 22 is located and then pulling horizontally outward to increase the length of extension of slider or pushing horizontally inward to decrease the length of extension of slider. Once the user has selected a desired length of extension the user then lowers the distal end of the slider, which then allows toothed member 24 to contact and engage with the lower edge of opening 18, thereby firmly holding the slider in place.

Referring now to FIG. 3, the above operation of each slider is more clearly illustrated looking directly down the length of sliders 30 a and 30 b disposed within I-beams 32 a, 32 b, and 32 c. Slider 30 a on the left has been lifted by an operator to its upward position where it can be retracted or extended, whereas slider 30 b on the right is in the locked lower position held firmly in place by contact of toothed member 34 b on edge 36 b, which represents the lower edge of opening 18 from FIGS. 1 and 2. Toothed members 34 a and 34 b are located on the bottom of t-shaped members 33 a and 33 b, which attach to the center of sliders 30 a and 30 b and project downward.

Vertical and lateral movement of slider 30 a and 30 b is limited by use of back plates 31 a and 31 b because the back plates fill the interior spaces between I-beams 32 a, 32 b, and 32 c, as indicated by the shaded portions of FIG. 3. In other words, back plates 31 a and 31 b are sized to fill the entire space between I-beams 32 a, 32 b and 32 c so that sliders 30 a and 30 b are held firmly in an upright position without any side-to-side or up and down movement. Although the embodiments of FIGS. 4 and 5 would include a back plate, none is shown so that the other components in FIGS. 4 and 5 can be more clearly illustrated.

Properly sized back plates 31 a and 31 b allow substantial movement of sliders 30 a and 30 b in one direction only, which is inward and outward along the interior surfaces of I-beams 32 a, 32 b, and 32 c. For added stability, back plates 31 a and 31 b also contain a lower lip 37 a and 37 b along their lower edges designed to fit between the bottom edges of I-beams 32 a, 32 b, and 32 c. It is important to note that, while back plates 31 a and 31 b prevent vertical movement of the inner portion of each slider (the distal end opposite rubber stop 22), each back plate also allows the small and necessary vertical movement of the outer end of each slider (distal end with rubber stop 22) needed to lift the distal end of each slider to extend or retract the slider. In this manner, each slider is allowed minimal but sufficient vertical travel on the distal end containing rubber stop 22, so that toothed members 34 a and 34 b pivot perpendicular to their own axis when an operator lifts the end of a slider to extend or retract that slider.

While slider 30 a is shown in the lifted position to allow its extension or retraction, slider 30 b is shown in the resting position where movement of the slider is prevented. As slider 30 b is lowered by an operator into the position shown, toothed member 34 b engages the lower edge 36 b of the opening of the stringer indicated by the dashed line. As both toothed member 34 b and lower edge 36 b are both generally made of rigid metal, contact between the two prevents further horizontal extension or retraction of slider 30 b. The weight of slider 30 b is generally sufficient to maintain the necessary contact between 34 b and 36 b so that movement of the slider is prevented.

Referring now to FIG. 4, an alternate embodiment of the toothed member is illustrated, wherein the toothed member pivots about its parallel axis and is held in place by a pivoting socket and compressible spring. I-beams 42 a, 42 b, and 42 c hold sliders 40 a and 40 b in place. Slider 40 a is shown with the pivoting toothed member 44 a at rest and held in place by spring 48 a. T-shaped member 45 a contains a pivoting socket 47 a designed to receive toothed member 44 a and to allow toothed member 44 a to pivot so that the toothed member is rotatable about its parallel axis. This differs from the fixed-toothed member 33 a shown in FIG. 3, which rotates about a perpendicular axis to engage and disengage.

Slider 40 b is illustrated with pivoting toothed member 44 b rotated into an unlocked position, whereby spring 48 b is compressed. Toothed member 44 b may be rotated from locked to unlocked in a number of ways. In one embodiment, an operator may simply reach under the edge of rubber stop 22 (shown in FIGS. 1 and 2) and apply upward lateral pressure on toothed member 44 b to compress spring 48 b and rotate toothed member 44 b about its parallel axis into the retracted position as shown. In this manner toothed member 44 b no longer contacts edge 46 b so that slider 40 b is free to be extended or retracted as desired.

Referring now to FIG. 5, another embodiment is illustrated for engaging a pivoting toothed member. Operator handle 51 a is inserted into opening 53 a and placed in its operating position so that distal end 59 a is in contact with a side portion of toothed member 54 a. The operator may then twist the handle 51 b as shown on the right so that distal end 59 b contacts the edge of 54 b, thereby pivoting toothed member 54 b so that it rotates about its parallel axis. This movement unlocks slider 50 b by preventing contact of toothed member 54 b with edge 56 b so that an operator is then free to extend or retract slider 50 b in normal use.

Once slider 50 b is extended or retracted into a desired position, the operator then twists the handle 51 b in the opposite direction to return the toothed member to its resting position, as indicated by 54 a. Compression springs 58 a and 58 b resist the rotation of toothed members 54 a and 54 b to force toothed members 54 a and 54 b back into a vertical position, as illustrated by 54 a, once the operator twists the handle back to its original position, as indicated by 51 a.

Referring to FIG. 6, an embodiment of the invention in use is illustrated to provide a three-sided adjustable work platform 100 for maintenance on a helicopter. Work platform 100 comprises two primary sections—fixed platform 110 and adjustable platform 120. Fixed platform 110 holds the various sliders described above. Once helicopter 115 is rolled into position at the center of work platform 100, those sliders are extended to form the adjustable platform 120 around the irregular outer surface of helicopter 115 as illustrated in FIG. 6. In this manner, a safe, inexpensive, and quickly established adjustable work surface is provided to facilitate maintenance on the helicopter.

These illustrated examples are offered by way of illustration of the invention's versatility and not meant to limit the invention in any way. The present invention may be embodied in other specific forms without departing from its spirit of essential characteristics. The described embodiments are to be considered in all respects only illustrative and not restrictive. The scope of the invention is therefore indicated by the appended claims rather than by the foregoing description. All changes which come within the meaning and scope of equivalency of the claims are to be embraced within their scope. 

What is claimed is:
 1. An adjustable work platform for carrying heavy loads in a stable manner comprising: a fixed platform with a front side and a back side opposite thereto comprising: a first stringer along said front side comprising defined openings therein; a second stringer along said back side; and a multiplicity of I-beam guides spanning between said first stringer and said second stringer; and an adjustable platform extendable from said fixed platform comprising: a slider received by adjacent I-beam guides and disposed to reversibly extend through one of said openings comprising: a toothed member that reversibly engages with said first stringer thereby restricting sliding of said slider; and a back plate attached to said slider, to limit the length of extension of said slider through said one of said openings.
 2. The work platform of claim 1 wherein said toothed member is rotatable about a perpendicular axis to said toothed member.
 3. The work platform of claim 1 wherein said toothed member is rotatable about a parallel axis to said toothed member.
 4. The work platform of claim 1 wherein said back plate limits the lateral and vertical movement of said slider to provide increased stability of said slider.
 5. A method of providing a work platform for carrying heavy loads while accessing an irregularly shaped large object comprising the steps of: providing an adjustable platform comprising a fixed platform with a front side and a back side opposite thereto, said fixed platform comprising a first stringer along said front side with defined openings therein, a second stringer along said back side, and a multiplicity of I-beam guides spanning between said first stringer and said second stringer; and an adjustable platform extendable from said fixed platform comprising a slider received by adjacent I-beam guides and disposed to reversibly extend through one of said openings, said adjustable platform further comprising a toothed member that reversibly engages with said first stringer thereby restricting sliding of said slider; and a back plate attached to said slider, to limit the length of extension of said slider through said one of said openings; moving a large object to within a predetermined separation distance of said platform; and extending said adjustable platform from said fixed platform, thereby minimizing said separation distance.
 6. The method of claim 5 further comprising the step of applying a lateral pressure to said toothed member to engage and disengage said toothed member from said first stringer.
 7. The method of claim 5 further comprising the steps of inserting a handle into said slider, engaging said toothed member with said handle, and reversibly disengaging said toothed member from said first stringer. 